Analysis of the interaction between risk factors for construction works on an example of the small experience of labourers

The successful course of any enterprise depends on materializing or non-risk factors. These factors affect not only the success or failure of the venture, but may also interact with each other. This paper describes the interactions between the factor "low experience of labourers" and six groups of other risk factors. The results of the analysis are presented in tabular form. The work was ended with conclusions and suggestions for further scientific and research work.


Introduction and purpose of the work
The successful course of any enterprise depends on materializing or non-risk factors. These factors affect not only the success or failure of the venture, but may also interact with each other. This leads to their mutual strengthening or weakening of the impact on the entire undertaking. Descriptions of such interactions can be found in literature sources from such areas as medicine [1] or social sciences [2]. Also in construction, this issue is increasingly being analyzed [3]. Determining the interaction between risk factors can be very useful, for example when estimating the execution times of construction works. It should be added that in such analysis one should focus primarily on strengthening the negative effects. This is an analogy to the principle known from the cost estimation of construction works, where the goal is to determine the value of the investment under the least favorable conditions. If the pessimistic scenarios do not materialize, the calculated cost surplus becomes an additional profit for the contractor. Similarly, when estimating the execution times of construction works, if the calculated values prove to be too large, the contractor will gain additional time to even check the work carried out or transfer the investment ahead of schedule. In this paper, the authors decided to present the issue on the example of the interaction between low experience of labourers and other risk factors.

Determining the set of risk factors
Before starting to determine the interaction between risk factors, a set of risk factors should be established that affect the time of construction work and will be included in the analysis. For this purpose, first identify the risk factors and then subject them to a qualitative analysis [4]. The mentioned activities, for Polish conditions, were carried out in publications [5,6,7]. The results from the above-mentioned works were merged and submitted to the opinion of building experts who manage large construction projects on a daily basis. What's more, the set of factors has been divided into thematic subsets. The effect of the activities carried out is shown in Table 1. Table 1. Selected set of risk factors that will be analyzed in terms of interaction with the factor "low experience of labourers" [own elaboration].
1. Risk factors related to logistics and resources. 1.6. Delays in the delivery of materials.

Risk factors related to administrative and legal aspects.
2.1. Difficulties with obtaining a permit for the execution of construction works.

No investor's decision.
3.2. The dispute between the general contractor and the investor.
3.3. The dispute between the general contractor and the subcontractor.
3.4. Changes in the project at the investor's request.

Risk factors related to financial and payroll aspects.
4.1. Investor delays in payments.

4.2.
Investor's difficulties in obtaining funds for investment financing.

Risk factors related to the construction environment.
6.1. Unfavorable weather conditions. 6.2. Unfavorable random event (eg accident, protests of the local community).

Analysis of the interaction of the factor "low experience of labourers" with other risk factors
After determining the set of risk factors that interact with the factor "low experience of labourers", it is necessary to begin describing the mutual impact for individual groups of risk factors. The analysis should take into account how other factors will reinforce the negative consequences of the low experience of labourers, which will translate into a decrease in the productivity of their work. In addition, it should be specified how the low experience of workers will strengthen the negative consequences or increase the severity of other risk factors [8].

The influence of risk factors on the analyzed risk factor
Improper logistic management can in extreme situations increase the small experience of labourers. This situation occurs if the persons supervising the investment do not have enough human resources or significant delays in providing it. In both cases, due to the limited availability of workers, a situation may arise where construction workers with no experience are employed under time pressure.

The influence of the analyzed risk factor on the other risk factors
The limited experience of construction workers is of moderate importance in the case of linking it to resource management. At the beginning, it should be pointed out that workers with little experience do not usually have tasks related to placing orders for materials. A separate issue is the limited decisiveness of these workers when deciding on personnel issues. The authors point out, however, that the employee's limited experience may cause inaccuracies and errors in informing decision-makers about the demand for resources. This is related to the lack of a proper assessment of the situation that is acquired through empirical experience.

The influence of risk factors on the analyzed risk factor
Difficulties in obtaining a building permit can have a significant impact on the risk of limited experience of construction workers only to a limited extent, in specific conditions, often subject to timely payment. If the entity paying the remuneration directly to the employee (general contractor, subcontractor or investor) does not have sufficient funds, then a situation may arise where the employee is left without remuneration. Undoubtedly, such a situation has a very strong negative impact on workers and will translate into their dissociation, stress and, as a result, a decrease in productivity. The phenomenon will be additionally intensified if the worker has serious financial obligations (credit, family, care for someone / on something).

The influence of the analyzed risk factor on the other risk factors
The authors did not find a direct impact of the factor "low experience of labourers" on delays in making payments by the investor or obtaining funds for financing the entire project. Therefore, there is no interaction in this direction.

The influence of risk factors on the analyzed risk factor
Improper management can affect the severity of the analyzed risk factor in two ways. The first considered situation can take place when the manager's mistakes are so serious that experienced workers, due to unfavorable working conditions, decide to resign from it, and staff shortages are supplemented with new, less experienced workers. The second situation occurs when inexperienced workers achieve low efficiency, while additional chaos associated with poor management (incorrect or contradictory orders from superiors) translates into an even greater decline in the efficiency of labourers [9].

The influence of the analyzed risk factor on the other risk factors
Inexperienced labourers can only affect some of the identified risk factors within the group related to improper construction management. Emphasize the impact on the possibility of delays on previous work plots and problems with the coordination of work. In both cases, the workers' small experience can activate the threats described by the aforementioned risks.

The influence of risk factors on the analyzed risk factor
According to the authors, neither unforeseen events nor weather conditions affect the experience of labourers. Risk factors related to the construction environment are largely random, hence the lack of interaction between them and experience. However, they can have a very large impact on the severity of the effects of low experience, which is the low productivity of workers. Unfavorable weather conditions (rainfall, very low or very high temperature values, significant wind intensity) practically always cause an additional drop in employee productivity. This phenomenon is relatively unaffected by workers performing work inside the building, when at least a closed shell is obtained. However, the impact of random events will primarily depend on the type of individual events. For example, an accident can significantly lower the brigade's morale, and protests of the local community, unless they take place at the place of work, will not further reduce workers' productivity.

The influence of the analyzed risk factor on the other risk factors
The low experience of labourers usually translates into an increase in recorded accidents on the construction site. These are often derived from the lack of prudence, bravery, willingness to facilitate work in a prohibited way, i.e. factors deriving from low experience. What's more, inexperienced workers usually less secure the robots against the negative impact of adverse weather conditions, thereby intensifying their impact on the progress of works.

Tabular summary of results
The results of the analysis from point 3 of this paper are presented in a synthetic way in the Table 2. To assess the mutual impact, linguistic variables were used: none, very low, low, medium, high, very high.